The present disclosure relates to an electrosurgical instrument for performing minimally invasive endoscopic surgical procedures involving coagulation of body tissues. More particularly, the present disclosure relates to a reusable, rotatable endoscopic bipolar electrosurgical forceps which can be completely disassembled for sterilization and reuse.
A hemostat or forceps is a simple plier-like tool which uses mechanical action between its jaws to constrict vessels and is commonly used in open surgical procedures to grasp, dissect and/or clamp tissue. Electrosurgical forceps are similar clamping devices which utilize both mechanical clamping action and electrical energy to effect hemostasis by heating the tissue and blood vessels to cause coagulation and/or cauterization.
Over the last several decades, more and more surgeons are abandoning traditional open methods of gaining access to vital organs and body cavities in favor of endoscopes and endoscopic instruments which access organs through small puncture-like incisions. Endoscopic instruments are inserted into the patient through a cannula, or port, that has been made with a trocar. Typical sizes for cannulas range from three millimeters to twelve millimeters. Smaller cannulas are usually preferred which presents a design challenge to instrument manufacturers who must find ways to make surgical instruments that fit through these smaller cannulas.
Certain surgical procedures require cutting blood vessels or vascular tissue. However, due to space limitations surgeons can have difficulty suturing vessels or performing other traditional methods of controlling bleeding, e.g., clamping and/or tying-off transected blood vessels. Very small blood vessels, in the range below two millimeters in diameter, can often be closed using standard electrosurgical techniques. If a larger vessel is severed, it may be necessary for the surgeon to convert the endoscopic procedure into an open-surgical procedure and thereby abandon the benefits of laparoscopy.
By utilizing an electrosurgical forceps, a surgeon can either cauterize, coagulate/desiccate and/or cut tissue and/or simply reduce or slow bleeding, by controlling the intensity, frequency and duration of the electrosurgical energy applied to the tissue. Generally, the electrical configuration of electrosurgical forceps can be categorized in two classifications: 1) monopolar electrosurgical forceps; and 2) bipolar electrosurgical forceps.
Monopolar forceps utilize one active electrode associated with the clamping end effector and a remote patient return electrode or pad which is typically attached externally to the patient. When the electrosurgical energy is applied, the energy travels from the active electrode, to the surgical site, through the patient and to the return electrode.
Bipolar electrosurgical forceps utilize two generally opposing electrodes which are disposed on the inner opposing surfaces of the end effectors and which are both electrically coupled to an electrosurgical generator. Each electrode is charged to a different electric potential. Since tissue is a conductor of electrical energy, when the end effectors are utilized to grasp tissue therebetween, the electrical energy can be selectively transferred through the tissue. Typically, during surgery, the end effector must be manipulated at various angles of rotation depending upon the desired angle of cutting and/or coagulating. As a result, instruments have been developed which include rotatable end effectors which are rotated by a knob located in general proximity to the user""s hand during operation.
It has also been found that cleaning and sterilizing many of the prior art bipolar instruments is often impractical as electrodes and/or insulation can be damaged. More particularly, it is known that electrically insulative materials, such as plastics, can be damaged or compromised by repeated sterilization cycles. Several instruments have been proposed in the past which are dismantleable and include replaceable components which facilitate cleaning and sterilization. However, it has been seen that as instruments increase in complexity, e.g., the addition of rotatable components, dismantling these instruments for cleaning and sterilization becomes difficult and often requires more than a rudimentary knowledge of the interworkings of the instrument and/or requires a series of intricate mechanical manipulations to disengage the more sensitive elements, e.g., the electrode.
Several bipolar endoscopic instruments are known which include rotatable elements and/or are dismantleable for cleaning purposes. For example, U.S. Pat. No. 5,716,354 to Hluchy discloses a rotatable bipolar instrument which includes a rotatable coupling and a separate knob which when depressed disengages the electrical tube from the instrument. A separate jack is used to rotate the instrument. U.S. Pat. No. 5,456,683 to Fritzsch et al. discloses a dismantleable medical instrument having a button for disengaging the electrical tube but is not rotatable.
Thus, a need exists to develop a rotatable bipolar instrument which is both simple to use and simple to assemble and disassemble for cleaning and sterilization purposes.
The present disclosure relates to a rotatable bipolar forceps for clamping and coagulating tissue which includes a housing and an electrode which is selectively removable from the housing for connecting a pair of laws to a source of electrical energy. The forceps further includes at least one handle attached to the housing for imparting movement to a shaft which causes the jaws to move from a first open position wherein the jaws are disposed in spaced relation relative to one another to a second clamping position wherein the jaws cooperate to grasp tissue therebetween. A rotating member rotates the electrode and the jaws relative to a longitudinal axis disposed through the housing and releasably couples the electrode to the housing.
Preferably, the forceps further includes an outer shaft which is removably coupled to the housing and an inner shaft disposed within the outer shaft which is movable relative to the outer shaft upon movement of the handle. The inner shaft is preferably dimensioned to house the electrode therein and is insulated. It is envisioned that movement of the inner shaft relative to the outer shaft causes the jaws to move from the first position to the second position.
In one embodiment of the present disclosure, the rotating member includes a lever which couples to a distal end of the electrode and imparts rotational movement to the electrode. A spring-release mechanism or the like may be employed to releasably couple the lever to the electrode. Preferably, the lever rotates the electrode and, therefore, the jaws, about 60 degrees on either side of the longitudinal axis.
In another embodiment, the rotating member includes a guide clip which controls the rotational movement of the lever. Preferably, the guide clip includes an arcuatly-shaped slot disposed therein for guiding the rotational movement of the lever. In one particular embodiment, a spring biases the lever in a normal position relative to the longitudinal axis.